U.S. patent application Ser. No. 12/701,304, filed Feb. 5, 2010, and U.S. Provisional Patent Application No. 61/154,280, filed Feb. 20, 2009, the disclosures of which are hereby incorporated herein by reference in entirety, disclose personal hydration systems comprising a hydration bladder for holding a liquid. A control valve assembly includes a valve body provided with a first inlet port in communication with the liquid in the hydration bladder, a second inlet port and an outlet port for dispensing at least the liquid from the hydration bladder therefrom. The control valve has a reservoir holding an additive and being mounted to the second inlet port of the valve body such that the additive is in communication with the second inlet port. The control valve assembly also includes a valve core mounted within the valve body to establish at least either a single flow condition of the liquid or a mixed flow condition of the liquid and the additive. The valve body and the valve core cooperatively define a liquid circulation arrangement directing flow from the hydration bladder into the reservoir to enable circulation and form a mixture of the liquid and the additive in the reservoir deliverable to the outlet port.